#include<iostream>
#include<vector>
#include<queue>
#include<cstring>
#include<cmath>
#include<map>
#include<set>
#include<cstdio>
#include<algorithm>
#define debug(a) cout<<#a<<"="<<a<<endl;
using namespace std;
const int maxn=2e3+100;
typedef long long LL;
const LL inf=0x3f3f3f3f;
inline LL read(){LL x=0,f=1;char ch=getchar();	while (!isdigit(ch)){if (ch=='-') f=-1;ch=getchar();}while (isdigit(ch)){x=x*10+ch-48;ch=getchar();}
return x*f;}
map<double,double>map1[maxn];
struct P{
   double x,y;
}p[maxn];
double get(LL i,LL j)
{
	LL y=p[i].y-p[j].y;
	LL x=p[i].x-p[j].x;
	if (!x)return 100000;
	LL gd=__gcd(x,y);
	x/=gd;
	y/=gd;
    return (y*1.0/x);
}
int main(void){
   cin.tie(0);std::ios::sync_with_stdio(false);
   LL n;cin>>n;
   LL tot=n*(n-1)*(n-2)/6;
   for(LL i=1;i<=n;i++){
      cin>>p[i].x>>p[i].y;
   }
   for(LL i=1;i<=n;i++){
       for(LL j=i+1;j<=n;j++){
           double k=get(i,j);
           map1[i][k]++;
       }
   }
   LL ans=0;
   for(LL i=1;i<=n;i++){
       for(auto j:map1[i]){
           if(j.second>=2){
              ans+=(j.second)*(j.second-1)/2;
           }
       }
   }
   cout<<tot-ans<<"\n";
   return 0;
}
